cherry-pick tcp reset bug fix

diff --git a/0001-tcp-reset-sk_rx_dst-in-tcp_disconnect.patch b/0001-tcp-reset-sk_rx_dst-in-tcp_disconnect.patch
new file mode 100644 (file)
index 0000000..8c0648b
--- /dev/null
+++ b/0001-tcp-reset-sk_rx_dst-in-tcp_disconnect.patch
@@ -0,0 +1,43 @@
+From d747a7a51b00984127a88113cdbbc26f91e9d815 Mon Sep 17 00:00:00 2001
+From: WANG Cong <xiyou.wangcong@gmail.com>
+Date: Sat, 24 Jun 2017 23:50:30 -0700
+Subject: [PATCH] tcp: reset sk_rx_dst in tcp_disconnect()
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+We have to reset the sk->sk_rx_dst when we disconnect a TCP
+connection, because otherwise when we re-connect it this
+dst reference is simply overridden in tcp_finish_connect().
+
+This fixes a dst leak which leads to a loopback dev refcnt
+leak. It is a long-standing bug, Kevin reported a very similar
+(if not same) bug before. Thanks to Andrei for providing such
+a reliable reproducer which greatly narrows down the problem.
+
+Fixes: 41063e9dd119 ("ipv4: Early TCP socket demux.")
+Reported-by: Andrei Vagin <avagin@gmail.com>
+Reported-by: Kevin Xu <kaiwen.xu@hulu.com>
+Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
+---
+ net/ipv4/tcp.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
+index b5ea036ca781..40aca7803cf2 100644
+--- a/net/ipv4/tcp.c
++++ b/net/ipv4/tcp.c
+@@ -2330,6 +2330,8 @@ int tcp_disconnect(struct sock *sk, int flags)
+       tcp_init_send_head(sk);
+       memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
+       __sk_dst_reset(sk);
++      dst_release(sk->sk_rx_dst);
++      sk->sk_rx_dst = NULL;
+       tcp_saved_syn_free(tp);
+ 
+       /* Clean up fastopen related fields */
+-- 
+2.11.0
+

diff --git a/Makefile b/Makefile
index ce2bdca0b9c9bed03ee6cc3a5041859fe8c9e3f0..adf8c599defea21f5d5402c1bc4f7cd358a1a3e1 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -246,6 +246,7 @@ ${KERNEL_SRC}/README: ${KERNEL_SRC_SUBMODULE} | submodules
        cd ${KERNEL_SRC}; patch -p1 < ../cgroup-cpuset-add-cpuset.remap_cpus.patch
        cd ${KERNEL_SRC}; patch -p1 < ../0001-netfilter-nft_set_rbtree-handle-re-addition-element-.patch # DoS from within (unpriv) containers
        cd ${KERNEL_SRC}; patch -p1 < ../0001-block-fix-bio_will_gap-for-first-bvec-with-offset.patch
+       cd ${KERNEL_SRC}; patch -p1 < ../0001-tcp-reset-sk_rx_dst-in-tcp_disconnect.patch
        sed -i ${KERNEL_SRC}/Makefile -e 's/^EXTRAVERSION.*$$/EXTRAVERSION=${EXTRAVERSION}/'
        touch $@